Rifts in time and space, tentacles and teenage angsts
by LaTeamBakaUsagi
Summary: Never let your children alone in your TARDIS. (set after the end of season 4)
1. Chapter 1

**First Chapter**

He had done it! After several months of work, the Doctor had finally recreated a TARDIS, thanks to the cutting the Doctor – well, the original one, the real Time Lord – had given to him*. He had replanted the cutting and it had grown remarkably quickly, as Donna had explained to him. He had then constructed his ship around it, and here it was: a new TARDIS, working perfectly fine, and ready to take them anywhere and anytime in the universe. The Doctor was eager to set off on an adventure again; these ten years or so on Earth, living a normal life, had been quite boring. Even if he had Rose with him and, later on, their two children, Donna and Ian, he was not made for this kind of sedentary life.

As soon as the TARDIS was finished, the whole family went on board and set off to explore the universe. The shimmering waterfalls of Centauria IV, the flying fish of Aryadell, the singing mountains of Nelidya, Middle Age on Earth, the fifty-second century… They had met the Ood, talked to Charlie Chaplin, ran away from Sontarans and Vastha Nerada… The Doctor had even accidentally gotten himself engaged with Princess T'kirx, from the Xilirian Empire – much to Rose's dismay.

The Doctor was delighted with his new adventures. His only disappointment was the fact that he hadn't succeeded in giving her original shape to the TARDIS; the spaceship did now look like a huge sailboat. The Doctor had however achieved the creation of an interface that allowed the TARDIS to talk directly with her crew.

Two years after their first journey on board of the new TARDIS, the whole family went to the peaceful planet of Apalapucia. Donna and Ian were respectively thirteen and twelve years old, and they were starting to be a bit bored; of course the journeys were great, but they were at this age when one starts to want to discover the world on their own, without having their parents around.

Rose and the Doctor were gone on a lovers' walk (which generally consisted in escaping fifteen aliens' attacks and saving the world four times in one day), leaving their children alone in the TARDIS.

As soon as they were alone, Donna turned to her brother:

"What if we left?"

"What? Like that? Without telling the parents?"

"Well, yeah! We could go together, travel where we want, and then we would go back at this hour here, and the parents wouldn't even realize that we had left!"

Ian was a bit anxious first, but he was quickly convinced by his sister. When your father was a Time Lord (well, almost a Time Lord), the adventure was always calling you.

The two children hurried towards the TARDIS's console and started touching to all the controls, despite their obvious lack of experience in the subject. They could not care less about the words of the TARDIS's interface, which was desperately trying to make them change their mind about going away alone.

Donna pressed a button, and the TARDIS activated.

* * *

 _A few years ago, in another universe_

Jack would have recognized that so particular sound anywhere. There was no possible mistake: the TARDIS was coming. The Doctor must have decided to stop in Cardiff to recharge his ship on the rift that ran beneath the city, as usual. The captain left his office immediately; anyway, since Ianto's death, he avoided as much as he could to stay in there. Too many painful memories were piled up there.

Jack went outside, his coat tucked under his arm, and walked up to the TARDIS, a bit unsure of what he was doing; after all, the last time he had done that, he had ended up at the end of the universe and had lived a year which, for the rest of the world, had never existed. As he reached the ship disguised as a police-call box, the Doctor went out. A small smile played on his lips when he saw Jack.

"Captain!"

"Doctor! How are you?"

The two men greeted, each of them finding comfort in the presence of the other after all the losses they had gone through during these last years – Donna and Rose (a second time) for the Doctor, Ianto for Jack, and so much more… Seeing each other again seemed to make their lives a bit more stable. However, they kept the talk on light subjects, as usual.

The Doctor had to wait for a dozen of hours before the TARDIS was fully recharged, so they went in a nearby pub to have a drink. The Doctor ordered a tea while Jack took a whiskey. They sipped their drinks, talking about everything and nothing all the same. After a while, Jack asked the Doctor if he had found a new companion. The Time Lord's face grew dark.

"I haven't looked for one," he answered. "I'm not ready to lose someone again."

"Well, in that case, that's a piece of luck I'm immortal," Jack replied, his self-assurance probably due to the quantity of alcohol he had absorbed before.

The Doctor stared at him, evidently taken aback, before he pulled himself together.

"That's a piece of luck indeed," he said nonchalantly.

It was Jack's turn to be taken aback.

"What?"

"I'd need someone to… (he rapidly searched for a pretext, not willing to admit how much he felt lonely in the TARDIS) …accompany me on Xeros. They're organizing a party in honor of their Empress, and I decently can not go alone, they would feel insulted."

Jack arched an eyebrow.

"Are you really proposing me what I'm thinking you're proposing me, Doctor?"

The Doctor rolled his eyes with a sigh.

"Jack… You haven't changed a bit."

"Why would I change someone who's as perfect as me?" Jack joked.

The Doctor ignored him.

"So, are you okay for that?" he asked.

Jack flashed a wide grin.

"Of course I am."

* * *

* See the deleted scene at the end of season 4: watch?v=7fixNsuYRmg


	2. Chapter 2

**Chapter Two**

 _Present time, somewhere in the universe_

"Are you sure it is supposed to do that?" Ian asked his sister.

"Absolutely, don't worry about it!" Donna replied, without paying attention to the alarming beeps of the TARDIS.

She kept on pressing several levers when suddenly, a bright, white light overwhelmed the ship, which swerved abruptly. The two children were projected backwards and they heard a strange worrying noise, as if the universe itself was whining. During a moment which felt like hours, the TARDIS tossed them around so hard they could not stand up.

"I still think it's not supposed to do that!" Ian shouted while grabbing firmly the ship's console.

"Come off it! It's hardly worst than Dad's driving!" Donna replied.

A huge shock shook the whole structure of the TARDIS, and the ship finally went still. The two children stood up with difficulty and walked towards the door, while the interface muttered to itself about teenagers and their irresponsibility. Ignoring the TARDIS's mumblings, Donna and Ian opened slightly the door and peeked outside.

They were standing in the middle of space, light years away from the closest planet; yet, they had embedded themselves into a police callbox that was floating there.

"Hold on a minute, Donna… Isn't that the original TARDIS? You know, the one which belongs to Dad's double?" Ian asked.

"But what is it doing in our dimension? You know as well as I do that there's no way to go from one universe to the other anymore!" Donna answered, perplexed.

 _In the meantime, in the other TARDIS…_

"What have you done again, Jack?!" the Doctor exclaimed when a violent tremor shook the TARDIS.

"Me? Nothing! And why would it be my fault, anyway? I'm not the one who's driving, in case you haven't noticed! I wasn't even in the commands' room!" Jack replied while entering the main room of the ship.

"What is it, then?" the Doctor wondered.

"It came from outside, didn't it?" Jack pointed out.

The Doctor nodded.

"We should go and see."

He grabbed his long brown coat, flippantly laid in a corner, before opening the TARDIS's door with a theatrical gesture. He stopped dead when he saw the cause of the shock: another TARDIS which looked like a sailboat, with two teenagers on its board, had collided with them. But what was doing another TARDIS in this dimension? This was not normal. Neither was the age of its pilots; they were far too young to know how to steer a ship.

There was a long moment of silence, during which the Doctor and the two children stared at each other, astounded. Finally, it was Jack who broke it:

"Hello!"

The Doctor spun round.

"Don't you even dare!" he exclaimed sharply.

"I was just saying hello!" Jack replied, offended. "I wasn't flirting! They're a bit young for me, all the same," he added jokingly.

"Da… Daddy?" Ian said, when he was finally able to speak again.

"What?" the Doctor exclaimed.

Jack turned to his friend: "It seems that you hid things from me, Doc…"

The Doctor ignored him and watched the children more closely. And that is when he understood: they must have been the children of Rose and his 'duplicate' – that would explain both the "daddy", the familiar features of the teenagers, and the sailboat-TARDIS. But what the hell were they doing in this dimension?

The Time Lord had a bad feeling which was confirmed when he spotted the tear in space-time, behind the other ship. _That_ was why you must not entrust your TARDIS to children, he thought. It ended up by endangering the whole universe. With a sigh, the Doctor made the two children enter his own ship. They needed to have a little talk about their arrival in this universe.

"So, you are the children of Rose and… the Doctor?" the Doctor asked when the children had finished presenting themselves and telling their story quickly. "And you've decided to go alone in your parents' TARDIS?"

"In a nutshell, yes," Donna admitted.

"Do you only realize how irresponsible you've been?!" the Time Lord exclaimed. "You created a rift in the space-time's web! And you're putting every universe in danger because of that!"

"We didn't know," Ian apologized piteously.

The Doctor sighed.

"And now I have to repair all that."

He hesitated, then asked: "By the way… How are your parents?"

He had to ask. The last time he'd seen Rose dated back to ten years or so ago, but he kept on thinking about her almost every day. No matter how many times he said to himself she was happy with his duplicate in their parallel dimension, he still missed her so much.

"They're fine," Donna answered.

"Well, they were fine before discovering we had left with the TARDIS," Ian whispered with a grimace.

The Doctor wanted to ask other questions, to ask for details, but he didn't know how to start. Finally, he sighed and told the children!

"We have to repair what you've caused with your foolishness. To do that, I need you to bring me all these items…"

He pulled a list from his pocket and gave it to Donna, while indicating her where they'd be able to fine all the items. In truth, he did not really need them, but he simply wished to be alone for some time in order to take in all that had just happened.

"But…" Ian began.

"No talking," the Doctor interrupted him. "We've already lost too much time."

Donna took her brother by the arm and dragged him along in the TARDIS's labyrinth of corridors, leaving the Doctor and Jack alone in the controls' room.

As soon as the two children had left, the Doctor leant on heavily on the TARDIS's console.

"You alright, Doctor?" Jack asked, walking towards his friend.

"Yes, I'm alright," the latter said with a really not convincing tone.

"Doc…" Jack sighed. "Tell that to others, but not to me."

The Captain knew well that he wasn't alright – which was understandable: the Doctor had every reason of being shaken. Seeing the children that you could have had if History had been different would trouble anybody.

"They look so much like her," the Doctor said at last. "And they… they look like me, too. Well, they look like my duplicate."

He sighed.

"They remind me of her. Actually, they remind of what… what I could have had. It's harder than I thought."

Jack put his hand on the Doctor's shoulder, hoping to comfort him. He knew that his friend had never really recovered from losing Rose, and he would have liked to do more to help him; but he did not really know what to do and he was afraid of being rejected if he tried to hug the Doctor.

"I'm sorry," he said eventually.

The words rang hollow, but the Doctor nodded, grateful.

"Thanks."

* * *

 _Thanks for reading!_

 _This story is planned to last eleven chapters (it may change while we write it, though)._

 _If you have any comment or advice, please don't hesitate to post them!_


	3. Chapter 3

**Chapter Three**

 _In the meantime, in the parallel universe_

Rose and the Doctor were walking along the shore, hand in hand. The waves were licking the polished stones while they headed back without hurrying to their TARDIS. For once, their lovers' walk unfolded without any problem – no infuriated aliens' attacks, no threats of world's end and, unusually, no sulky preteens. They would almost have missed it; it must be said that they weren't used to it.

Rose smiled and rose on tip-toe to plant a soft kiss on her companion's lips. He slid a hand in her blond hair while lovingly responding to her kiss. They prolonged the contact, enjoying this moment of intimacy, before returning to their ship.

Only there was a problem: when they came to the place where they had left their TARDIS, they saw neither ship nor children.

"Are you sure we really parked the ship here?" Rose asked the Doctor.

In truth, she was almost sure it was the right place, but she didn't want to admit what she was seeing – or, rather, _not_ seeing. The Doctor nodded with unusual seriousness, confirming her fears. The TARDIS had definitely vanished, along with their children.

"But… could someone have stolen the TARDIS?"

Rose was seriously beginning to panic. Danger was a part of her everyday life but, like every mother, she was really worried for her children. The Doctor shook his head.

"No," he answered. "The TARDIS wouldn't have left someone enter aside from us."

"What happened, then?"

The Doctor looked at Rose with a face that clearly meant: _I've got a theory about this, and you're not going to like it_.

"I think the children must have had activated something."

"But… willingly?"

"I don't think so, but that's a possibility," the Doctor answered.

"You told me that they didn't risk anything!" Rose exclaimed. "That the TARDIS would protect them, and that we could leave them alone safely!"

"How could I have known they'd activate the TARDIS?" the Doctor replied.

"Seriously? That's your apology? A ship full of buttons and levers, with two children alone inside, and you really thought they would not activate something?!"

"If you were so sure they would do something, why did you accept to leave them alone in the first place? Don't put all the blame on me!"

Rose was ready to reply, but she changed her mind. Her children were somewhere in the universe, alone in a quite unpredictable ship, and potentially endangered; this was not the time to argue with her companion (though he would get what was coming to him). She was about to say so to the Doctor, when he pointed to something behind her and said:

"However, I think we may have another problem…"

Rose turned around and gauged the scale of said problem: a huge rift, similar to the one which had trapped her in this dimension, was tearing the web of the space-time.

"Oh shit," she muttered. "Don't tell me that's linked to the disappearance of the TARDIS and our children?"

"I'm afraid it actually is," the Doctor answered.

He dipped into one of his pockets – which were, of course, bigger on the inside than on the outside – and pulled out a phosphorescent marker which he put on the ground.

"Fluctuating ionic injection's beacon, found in a market on Jaxkhatar. It should prevent the rift to close itself while we're on the other side."

"You don't want to simply close it?" Rose asked, perplexed.

"There's a high enough probability of Donna and Ian being on the other side; we should go and search them, or at least look for some clues to find where they might be."

"Okay." Rose nodded, decided, before thinking a bit and saying: "However, how exactly do you plan to cross the rift, without the TARDIS?"

"I… haven't thought about this detail yet," the Doctor answered piteously.

Rose sighed. It was such a typical answer from her companion.

"We should go back to the city," she said at last. "Maybe they have something that could help us."

 _At the same time, in the other universe…_

The alarm of the TARDIS went on, indicating a serious problem. The Doctor went away from Jack and ran to the screen.

"What's happening?" the immortal asked while peeking over his shoulder.

"When they came to this universe, Donna and Ian fragilized the structure of the space-time's web, which puts the very entirety of the multiverse in danger. The phenomenon they triggered can happen again at any time. And that's precisely the case now!"

"What do you mean by 'phenomenon', exactly?" The Captain asked before taking a sharp breath when he understood. "An opening rift?"

The Doctor nodded.

"And it seems that we were just pulled inside it!"

Jack thought that his companion was a bit too enthusiastic about the whole thing – but it was a typical reaction from the Doctor, after all: something strange and worrying threatens to destroy all the universes? Cool, let's hurry up to go in the middle of the chaos, so that we can study this phenomenon and save the world! And, after all, the Captain preferred seeing his Doctor in this mood than all depressed like he was just a few moments ago.

"It seems that there's a planet nearby," the Doctor said. "I'll try to land on it. It should be a bit more stable than our current situation."

The TARDIS was actually violently shaken. The Doctor pushed several buttons and pulled some levers, while Donna and Ian came back, holding the items they had been searching.

"Hold on!" the Time Lord exclaimed while hitting the TARDIS's console a last time with his hammer. "The landing will be rude!"

This was the case indeed; the two children were thrown against the commands, while the Doctor found himself half lying on Jack – who was rather enjoying the situation. However, the Time Lord stood up immediately and headed towards the console.

"Donna, Ian, you'll stay here while Jack and I will observe this planet. Above all, don't touch _anything_! And you, he added to the TARDIS, don't start up until we're back."

"But…" Donna began, obviously annoyed to have to stay behind.

"We should probably do as he says," Ian interrupted her; his lust for adventure had all but vanished after the recent events. "We promise we won't touch anything," he added for the Doctor.

The latter nodded before walking towards the TARDIS's door, followed by Jack.

A vast stretch of short and yellowed grass spread out before them, its monotony only broken by some small trees with mauve leaves. The area seemed utterly uninhabited, except for the small house a few hundreds of meters away from them.

They both looked at each other.

"Allons-y!" the Doctor exclaimed merrily, and they started walking towards the house.

Once they were arrived, the Time Lord pulled his sonic screwdriver from his pocket and unlocked the door. The lock clicked and produced some sparkles, and the door slid open. The two men entered the house. The room in which they stood was empty, except for the translucent capsule which contained a humanoid creature. It was laying on its back and plunged in a deep stasis's state, as was shown by the colorful lights which were blinking along the capsule. The creature was covered with thin blue scales, from the top of its smooth skull to the tip of its numerous tentacles.

"What species is it, Doc?" Jack asked, intrigued.

"I have no idea," his companion answered. "I've never seen a living being like this before."

"Why is it in stasis, do you think?"

"Well, there's only one way to find out," the Doctor answered, sonic screwdriver in hand.

While the Time Lord was checking the vital signs of the creature, while Jack was exploring the house, and while Donna and Ian were playing with the historical costumes in the TARDIS; in short, while nobody was paying attention to it, the rift between the two universes closed itself and vanished like it had never existed.

* * *

So here we are, at 4 a.m., publishing this chapter... Fanfictions will soon defeat us... (assuming that's not already the case!)

Anyway, we hope you enjoy this new chapter! :)


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